Exercise apparatus often include movable members which generate a substantial opposing force in response to being moved by an exerciser for strengthening muscles and/or increasing muscle tone. For example, the weight of bar bells provide a generally constant opposing force during the exerciser's range of movement. Other apparatus partially generate, independent of exerciser exertion, a repetitive movement for matching or aiding the movement of the exerciser to partially reduce the opposing force. For example, U.S. Re. Pat. No. 34,212 to Potts shows an upper body exercise apparatus having a vertically movable exerciser support platform in combination with chin and dip bars. Pneumatic pistons driven by an electric motor automatically raise and lower the platform for aiding the exerciser. The above apparatus, which can either provide a constant opposing force or generate independent forces, can possibly contribute to injury to the exerciser if misused.
In response to the foregoing, it is an object of the present invention to overcome the drawbacks and disadvantages of prior art exercise apparatus.